1. Technical Field
The present invention relates to an image processing apparatus, image processing method, and a computer readable storage medium, and in particular to an image forming apparatus, image processing method, and a computer readable storage medium for discriminating whether or not an image subject to processing is an image in which a processing target object is captured, or detecting a region in which a processing target object appears.
2. Related Art
Up until now, Histogram of Oriented Gradients (HOG) features are being widely employed in the field of object recognition (see Japanese Patent Application Laid-Open (JP-A) No. 2007-156626). HOG features are feature amounts arising from partitioning an image into plural regions and constructing a histogram of the gradient orientations of brightness in each of the regions. Since HOG features are extracted for each localized region, there is little influence from changes in illumination, and the Histograms of Oriented Gradients are robust to localized small geometric variations.
However, the HOG features described above are only able to express localized object shapes in a broad manner, and, since it is difficult to express high-order features included in object shapes, such as co-occurrences of adjacent outlines, there is the problem that image discrimination at high precession cannot be made.